var f,g:text;
    a:array[1..16,1..16] of longint;   
    s,ss,smax:longint;   
    k,i,j,n,m:byte;   
    x:array[0..16] of byte;   
begin  
     assign(f,'flip.in');   
     assign(g,'flip.out');   
     reset(f);   
     rewrite(g);
     readln (f,n,m);
     for i:=1 to n do begin
         for j:=1 to m do
             read (f,a[i,j]);
             readln(f);
     end;
     k:=1;
     while k>0 do begin
			if x[k]<2 then x[k]:=x[k]+1;
			if k=n then  
               			begin 
                  		ss:=0;   
                  		for j:=1 to m do 
					begin  
                  			s:=0;   
                  			for i:=1 to n do
						begin  
                      				if x[i]=2 then 							
							s:=s-a[i,j] 
							  else  
                         				s:=s+a[i,j];   
               					end;   
     					if s<0 then ss:=ss-s 
					       else ss:=ss+s;   
    					end;
    				if ss>smax then smax:=ss;
    				while x[k]=2 do 
						begin 
						k:=k-1; 
						end;
   				end 
			       else 
				begin 
				k:=k+1; 
				x[k]:=0; 
				end
  		 end;
  write(g,smax);
  close(f);
  close(g);   
end.